This is the WSJ story that Scott references in the campaign video:
https://www.wsj.com/articles/joe-biden-used-tax-code-loophole-obama-tried-to-plug-11562779300
According to the article, the Biden family uses S-corporations to report personal taxable income in a way which avoids paying an additional 3.8% medicare tax. This is completely legal due to the Affordable Care act. What this means is that Joe Biden saved himself from paying $500,000 in taxes as long as his S-corporation pays 'reasonable compensation' (a legal grey area, however this is still legal). It is also worth noting that the IRS is aware of these facts, yet is not interested in pursuing the president. Additionally, the article states that Biden has released his yearly tax forms on his campaign website. Therefore, the claim that Biden is a huge tax cheat is a bit misleading, and is unrelated to the Medicare or IRS policies brought up by the video.
Now, let's focus back to Rick Scott. If you are unfamiliar with Scott, he is literally the man behind the largest Medicare fraud in history (
https://www.justice.gov/archive/opa/pr/2003/June/03_civ_386.htm) in which his hospital HCA exploited Medicare to overcharge patients over $1 billion. Whatever this man says about Medicare, take it with a grain of salt.
Here is a video from 4 years ago of him smearing Democrat Bill Nelson with similar claims:
https://www.youtube.com/watch?v=qdpfLYnDhcU&ab_channel=ScottForFlorida
